When wireless communication devices such as mobile phones were first developed, most of them used analog signal transmission systems and therefore needed to operate only in the Analog Mobile Phone System (AMPS) band. Over the past few years, several developments have taken place in the field of wireless communication systems. A variety of digital transmission schemes have been developed to enable efficient and enhanced transmission of data over the wireless medium. Further, the size of wireless devices, including mobile phones, has reduced considerably.
To cater to the increasing utilization of the wireless medium, the radio frequency spectrum is divided into various segments, so that certain frequency bands are devoted to specific services. For example, separate frequency bands have been devoted to mobile phone traffic, satellite communication, radio communication and television signal communication.
With the advent of several digital transmission schemes in wireless devices, several frequency bands are being utilized for communication. These bands are separated and are utilized for different communication applications or schemes. Exemplary bands include the Global System for Mobile Communications (GSM) band, and the Universal Mobile Telecommunications System (UMTS) band. These bands offer certain advantages, and it is desirable to utilize wireless devices that operate reliably within these bands. In order to operate mobile phones reliably in these bands, antennas are required that may be precisely tuned to operate in the desired frequency band.
Conventional antennas that enable the precise operation of wireless devices such as mobile phones in the desired bands are typically external antennas that fit outside the body of the mobile phone. These are not popular with consumers. Further, these antennas only operate in a few frequency bands.